1. Field of the Invention
The present invention relates to a liquid crystal display device. More specifically, the invention relates to a liquid crystal display device with high contrast characteristics of the multi-domain system using spacers.
2. Description of the Prior Art
Active matrix liquid crystal display devices using active elements as represented by thin-film transistors (TFT) have now been widely used as display terminals of OA equipment since they are light in weight and have picture quality equivalent to that of cathode-ray tubes.
The display system of the liquid crystal display devices can be roughly divided into two. One is a system in which liquid crystals are sandwiched by two substrates having transparent electrodes and are driven by a voltage applied to the transparent electrodes, and light incident upon the liquid crystals and transmitted through the transparent electrodes is modulated to achieve display.
Another one is a system in which liquid crystals are driven by an electric filed which is nearly in parallel with the surface of a substrate between two electrodes that are formed on the same substrate, and light incident upon the liquid crystals through a gap between the two electrodes is modulated to provide display.
Features of the latter system have been disclosed in, for example, U.S. Pat. Nos. 5,576,867, 5,598,285, 5,786,876, 5,956,111 and Japanese Patent No. 02907137. Moreover features of a multi-domain system IPS (In-Plane Switching mode) liquid crystal display have been disclosed in, for example, U.S. Pat. No. 5,745,207.
In general, an orientation process that prepares an orientation film for controlling liquid crystal molecules is done by rubbing using a rotating rubbing roller on the surface of an orientation film. However, when spaces are formed on an orientation layer, an orientation process can cause alignment defects as a result of the differences in surface level. Specifically, when spacers are formed in the display region, an alignment defect can result in an improper image display.
Accordingly, an object of the present invention is to provide multi-domain system IPS (In-Plane Switching mode) liquid crystal display which have high contrast and do not suffer from improper image display. This invention provide a remarkable high contrast display (350:1) as compared to current model displays (200:1).
According to one aspect of the present invention, there is provided a black matrix formed between a pair of substrates and formed over a plurality of drain lines and gate lines, a plurality of spacers arranged under the black matrix, wherein a plurality of liquid crystal molecules are aligned to a boundary direction of the black matrix in the OFF state, and having a first group and a second group in the ON state, wherein a switching angle of the second group is opposite to a switching angle of the first group.
According to another aspect of the present invention, there is provided a plurality of liquid crystal molecules having a negative dielectric constant anisotropy and interposed between said pair of orientation layers, a black matrix formed over another of a pair of substrates in a matrix shape, a plurality of spacers formed between the black matrix and one of a pair of orientation layers, wherein said plurality of liquid crystal molecules having X direction of an initial orientation angle, and twisted to +Y direction and xe2x88x92Y direction when driving voltage is applied.
According to another aspect of the present invention, there is provided a plurality of liquid crystal molecules having a positive dielectric constant anisotropy and interposed between a pair of orientation layers, a black matrix formed over another of a pair of substrates in a matrix shape, a plurality of spacers formed between the black matrix and one of the pair of orientation layers, wherein a plurality of liquid crystal molecules having Y direction of an initial orientation angle, and twisted to +X direction and xe2x88x92X direction when a driving voltage is applied.
According to another aspect of the present invention, there is provided a plurality of liquid crystal molecules having a negative dielectric constant anisotropy and interposed between said pair of orientation layers, a black matrix formed over another of a pair of substrates in a matrix shape, a plurality of spacers formed between the black matrix and one of a pair of orientation layers, wherein said plurality crystal molecules having X direction of an initial orientation angle, and twisted to +Y direction and xe2x88x92Y direction when driving voltage is applied.